As Mariah strained to reach those high notes of her new song, Infinity, JLo was swiping through new photos and barely looked up at the stage.

While Las Vegas’ newest resident reached a climax, and Taylor could be seen mouthing ‘awesome’ to her new beau DJ Calvin Harris, JLo bopped her head but we weren’t getting the feeling that she was truly into it.

We saw you JLo! (Image: Splash)

She did clap at the end though. That’s saying something.

To be fair, Mariah has been fighting bronchitis but even still, according to viewers at home, she failed to deliver a good vocal performance.